There have been several initiatives at the Federal, State, and local levels that have identified fathers as important figures in combating poverty, attenuating the lost developmental potential of young children, improving the nutritional status and safety of children, and reducing experiences with violence during the early childhood years. Researchers from diverse disciplines have identified risks and protective factors within and external to the family that are associated with different dimensions of father engagement and child development outcomes. Despite these advances, little is known about how paternal proximal processes are linked to childhood outcomes and what factors within the family potentially mediate these links in families who participate and do not participate in relationship education. Using cultural-ecological, risk and resilience, and parenting theories/models and complier average causal effect estimates, the study proposes to use secondary data from the Building Strong Families (BSF) project to examine the associations between fathers' responsiveness, depressive symptoms, and experiences of inter-partner violence (IPV) and young children's social and language skills, and whether social support networks and relationship quality mediate these associations differently for families who participated and did not participate in relationship education. The findings from the proposed analyses should build on the preventative scientific approach to family interventions by providing insights into factors within families that serve a protective function against multiple paternal risks on childhood development. The results should be of interest to state and local agencies that focus on preventing developmental risks to children that are attributed to challenging home and neighborhood environments. Sample: BSF 15-month and 36-month data set of low-income families and children from diverse ethnic backgrounds. The total sample at baseline consisted of 5,102 unmarried, romantically involved couples. Measures: Paternal Responsiveness Intimate Partner Violence (IPV) Depressive Symptoms Relationship Quality Support and Affection Constructive and Avoidance of Destructive Conflict Behaviors Support Network Program Participation Childhood Outcome Measures ? Language Skills ? Behavior Problems Control Variables ? Co-Parenting ? Family Stability ? Poverty Status and Material Hardship ? Father's Age and Ethnicity